It follows strained relations between photographers and the Met over the way the media was treated at the scenes of the London bombings in July as well as other big news stories, such as the Paddington rail crash, going back several years.

Photographers’ representatives, who claimed the Met had been obstructing their members, took the initiative and approached the press bureau at New Scotland Yard two years ago.

Now new nine-point guidelines have been drawn up by a press/police working group including representatives of the British Press Photographers’

Association, the CIoJ and the NUJ, and were approved this week.

In the guidelines, the Met pledges: "Members of the media have a duty to report from the scene of many of the incidents we have to deal with. We should actively help them carry out their responsibilities provided they do not interfere with ours."

They also state: "Members of the media have a duty to take photographs and film incidents, and we have no legal power or moral responsibility to prevent or restrict what they record. It is a matter for editors to control what is published or broadcast, not the police. Once images are recorded, we have no power to delete or confiscate them without a court order, even if we think they contain damaging or useful evidence."

On death-knocking, the new code says: "If someone who is distressed or bereaved asks for police to intervene to prevent members of the media filming or photographing them, we may pass on their request, but we have no power to prevent or restrict media activity."

The new guidelines also say that where the Met puts cordons in place, it is "much better to provide the media with a good vantage point from which they can operate, rather than to exclude them" and that "members of the media do not need a permit to photograph or film in public places".

On the media side, journalists are urged to produce identification, such as the UK Press Card, and to obtain permission from the owner when accompanying police onto private property. It also states that giving the media access to crime scenes is a matter for the senior investigating officer.

BPPA chairman Jeff Moore said: "It is gratifying to see that after almost two years of work, these guidelines have been produced by the Metropolitan Police. We look forward to other forces around the country adopting and branding them as their own."

Chair of the CIoJ’s photography division, Paul Stewart, said: "By producing these complementary sets of guidelines we will be able to ensure that, without the media hindering the police in any way, the public are able to exercise their right to stay informed."

And John Toner, freelance organiser of the NUJ, added: "Although this process was started for and by photographers, the guidelines cover all frontline newsgatherers."